An endoprosthesis of the general type of the invention is known under the designation "Insall/Burstein" Total Knee System from a brochure of the firm Zimmer, USA. A single crosspiece located between the gliding surfaces of the tibia component serves as the guiding or conduction element for the femur component of this known endoprosthesis. When the joint is in the extended position, this crosspiece engages an opening in the hollow space defined between the gliding runners of the femur portion. With increasing flexure of the joint, this crosspiece comes out of engagement with this opening. Conduction of the gliding runners occurs exclusively when the flat lateral surfaces of the aforementioned crosspiece come into contact with the equally flat guiding surface of the femur component.
Disadvantages of this endoprosthesis are its insufficient guiding function, as well as only limited stress reducing capability of the crosspiece during weight shifting movements. High incidence of abrasion or wear on the parts which rest against each other as well as inadequately reproducible physiologic movement of the joint are the results of the structure of the known endoprosthesis.
The purpose of the present invention is to remedy these problems. In addition, an additional aspect of the invention is its use in facilitating the implantation of new parts or, if necessary, the replacement of worn out parts.